EJB中MySQL数据源的发布与使用

JBOSS中MySQL对应的配置文件：mysql-ds.xml事项（注意代码中&符号在XML中要转码成&amp）

 

<?xml version="1.0" encoding="UTF-8"?><!-- $Id: mysql-ds.xml 71535 2008-04-01 07:05:03Z [e-mail] $ --><!-- Datasource config for MySQL using 3.0.9 available from:http://www.mysql.com/downloads/api-jdbc-stable.html--><datasources> <local-tx-datasource> <jndi-name>itcastDS</jndi-name> <connection-url>jdbc:mysql://localhost:3306/itcast?useUnicode=true&characterEncoding=UTF-8</connection-url> <driver-class>com.mysql.jdbc.Driver</driver-class> <user-name>root</user-name> <password>123456</password><min-pool-size>5</min-pool-size><max-pool-size>100</max-pool-size> <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLExceptionSorter</exception-sorter-class-name> <!-- should only be used on drivers after 3.22.1 with "ping" support <valid-connection-checker-class-name>org.jboss.resource.adapter.jdbc.vendor.MySQLValidConnectionChecker</valid-connection-checker-class-name> --> <!-- sql to call when connection is created <new-connection-sql>some arbitrary sql</new-connection-sql> --> <!-- sql to call on an existing pooled connection when it is obtained from pool - MySQLValidConnectionChecker is preferred for newer drivers <check-valid-connection-sql>some arbitrary sql</check-valid-connection-sql> --> <!-- corresponding type-mapping in the standardjbosscmp-jdbc.xml (optional) --> <metadata> <type-mapping>mySQL</type-mapping> </metadata> </local-tx-datasource></datasources>

 

 

项目工程中对应META-INF目录下对应的persistence.xml配置文件（JPA规范）

<?xml version="1.0" encoding="UTF-8"?><persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0"> <persistence-unit name="myItcast" transaction-type="JTA"> <jta-data-source>java:itcastDS</jta-data-source> <properties> <property name="hibernate.hbm2ddl.auto" value="update" /> <property name="hibernate.show_sql" value="true"/> <property name="hibernate.formate_sql" value="true"/> </properties></persistence-unit> </persistence>

 

注意：

在某些环境下，persistence.xml中不需要具体的持久化配置信息即可运行（如下代码），之前在某些教程中看到过，按照此方法，部署到JBOSS后，做单元测试，死报错，后来加上相应<properties>配置信息后才正常，这个问题当时纠结了一整天才找到原因：

<?xml version="1.0" encoding="UTF-8"?><persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0"> <persistence-unit name="myItcast" transaction-type="JTA"> <jta-data-source>java:itcastDS</jta-data-source> </persistence-unit> </persistence>